package com.gy.def.utils;/**
 * Created by cyy on 2018/11/14 11:20
 * TODO
 */

import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * @ClassName AesEncryptUtil
 * @Description AES加密解密的工具
 * @author cyy
 * @date 2018/11/14 11:20
 * @Version 1.0
 */
public class AesEncryptUtil {

    //使用AES-128-CBC加密模式，key需要为16位,key和iv可以相同！
    private static String KEY = "fqj9shigedashabi";

    private static String IV = "fqj9shigedashabi";

    /**
     * @Description 加密方法
     * @author cyy
     * @date 2018/11/14 11:23
     * @param data 要加密的数据
     * @param key  加密key
     * @param iv   加密iv
     * @return java.lang.String
     */
    private static String encrypt(String data, String key, String iv) throws Exception {
        try {
            //"算法/模式/补码方式"
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            int blockSize = cipher.getBlockSize();

            byte[] dataBytes = StrUtil.toUTF8(data.trim()).getBytes("utf-8");
            int plaintextLength = dataBytes.length;
//            if (plaintextLength % blockSize != 0) {
//                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
//            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);

            return new Base64().encodeToString(encrypted);

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * @Description 解密方法
     * @author cyy
     * @date 2018/11/14 11:23
     * @param data 要解密的数据
     * @param key  解密key
     * @param iv   解密iv
     * @return java.lang.String
     */
    private static String desEncrypt(String data, String key, String iv) throws Exception {
        try {
            byte[] encrypted1 = new Base64().decode(data);

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes("utf-8"));

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] original = cipher.doFinal(encrypted1);
            return new String(original);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * @Description 使用默认的key和iv加密
     * @author cyy
     * @date 2018/11/14 11:22
     * @Param [data]
     * @return java.lang.String
     */
    public static String encrypt(String data) throws Exception {
        return encrypt(data, KEY, IV);
    }

    /**
     * @Description 使用默认的key和iv解密
     * @author cyy
     * @date 2018/11/14 11:22
     * @Param [data]
     * @return java.lang.String
     */
    public static String desEncrypt(String data) throws Exception {
        return desEncrypt(data, KEY, IV);
    }

}
